1. Week 8: Infectious Changes Stem cell theory Stem cell theory Interleukins Interleukins Neutrophilia Neutrophilia Monocytosis Monocytosis Neutropenia Neutropenia Leukoerythroblastic rxn Leukoerythroblastic rxn Shift to the left Shift to the left MGP and CGP MGP and CGP Toxic changes Toxic changes LAP LAP Lymphocytosis Reactive lymphocyte Turk cell Plasma cell Immunoblast IM (EBV) Protein ELP Eosinophilia Basophilia

2. Leukocyte Development Stem cell theory Stem cell theory  Proliferation  Differentiation  Maturation Leukocyte precursors Leukocyte precursors

6. Bacterial infection Neutrophilia with shift to the left Neutrophilia with shift to the left Toxic changes Toxic changes Leukoerythroblastic reaction Leukoerythroblastic reaction Monocytosis with chronic infection (eg, TB) Monocytosis with chronic infection (eg, TB) Neutropenia with overwhelming infection Neutropenia with overwhelming infection High LAP score High LAP score

7. LeukocytosisShift to the Left

9. Neutrophilia Mobilization of cells in the marginal granulocyte pool (MGP) to circulating granulocyte pool (CGP) Mobilization of cells in the marginal granulocyte pool (MGP) to circulating granulocyte pool (CGP) Bone marrow activity leads to leukemoid reaction Bone marrow activity leads to leukemoid reaction

10. Toxic Changes Toxic granulations: 1 o granules persisting to the older stages Toxic granulations: 1 o granules persisting to the older stages Dohle bodies: RNA Dohle bodies: RNA Vacuoles, not related to storage in EDTA Vacuoles, not related to storage in EDTA

11. Toxic Changes in Neutrophils

12. Viral Infection Lymphocytosis Lymphocytosis  Beware of pediatric reference ranges  Distinguish from CLL Reactive lymphocytes (ATL, virocytes) Reactive lymphocytes (ATL, virocytes)  Downey classes and Turk cell  Immunoblast  EBV associated with IM: do serology  Broad  increase in protein ELP

13. Lymphocytosis and Reactive Lymphocytes

15. Serum Protein Electrophoresis

16. Parasitic Infection and Allergy Eosinophilia in parasitic infection Eosinophilia in parasitic infection Eosinophilia and basophilia in allergy Eosinophilia and basophilia in allergy Note basophilia in CML Note basophilia in CML